Manganese
metal
Erosion of natural deposits; common in groundwater, particularly in low-oxygen wells.
EPA regulatory status
Legal limit (MCL)
No numeric MCL
Goal (MCLG)
Not set
No federal primary MCL. Regulated only by a non-enforceable Secondary standard (SMCL) of 0.05 mg/L (50 ppb) for aesthetic reasons (staining, taste). EPA also publishes a lifetime health advisory of 0.3 mg/L (300 ppb) and a 1-day advisory of 1 mg/L to protect infants. Absence of a primary limit is itself the finding.
Health effects
An essential nutrient at low doses. At high long-term levels, especially in infants, it is associated with neurological effects. Also causes black/brown staining and a metallic taste above the secondary standard.
This is general public-health information, not medical advice — consult your physician with any health concerns.
National violations
0
EPA's enforcement data (SDWIS/ECHO) records zero violations of Manganese's rule nationally. See this contaminant's regulatory status above for its current standard and compliance timeline — a zero count is not necessarily an all-clear.
How to remove Manganese
cation exchange
NSF/ANSI 44
Frequently asked questions
What is Manganese?
Manganese is a metal regulated in US drinking water. Erosion of natural deposits; common in groundwater, particularly in low-oxygen wells.
What is the legal limit for Manganese in drinking water?
No federal primary MCL. Regulated only by a non-enforceable Secondary standard (SMCL) of 0.05 mg/L (50 ppb) for aesthetic reasons (staining, taste). EPA also publishes a lifetime health advisory of 0.3 mg/L (300 ppb) and a 1-day advisory of 1 mg/L to protect infants. Absence of a primary limit is itself the finding.
What health effects does Manganese have?
An essential nutrient at low doses. At high long-term levels, especially in infants, it is associated with neurological effects. Also causes black/brown staining and a metallic taste above the secondary standard.
How many violations of Manganese limits are on record nationally?
EPA's enforcement data (SDWIS/ECHO) records zero violations of Manganese's rule nationally. See this contaminant's regulatory status above for its current standard and compliance timeline — a zero count is not necessarily an all-clear.
How do I remove Manganese from my water?
Filter technologies certified to reduce Manganese include: cation exchange (NSF/ANSI 44), reverse osmosis (NSF/ANSI 58). Look for a filter independently certified against the specific NSF/ANSI standard for this contaminant — general "reduces contaminants" marketing claims are not the same as a contaminant-specific certification.
Source: EPA National Primary Drinking Water Regulations · Data as of 2026-07-16